Last modified: Wed 12/31/1969 06:00:00 pm
CHEM 1515 Spring 2015 BCE1

This is our first BCE. It covers some material we discussed in CHEM 1314, and also some new stuff.

Do not press the RETURN or ENTER key while you are answering these questions. Your browser will interpret either the same as clicking on the Submnit key.

Answer all of the questions below. If you do not know an answer enter CNA. However, it will help me the most if you answer each question with your best intuition/idea about what would be a reasonable answer.

First Name:

Last Name:

Laboratory Section:

1. What does the term exothermic mean to you? In your brief description, use words like system, surrounding, reaction, heat, temperature, reactants, products. Note you do not have to use all those words, and you can use others.

2. What does the term endothermic mean to you? In your brief description, use words like system, surrounding, reaction, heat, temperature, reactants, products. Note you do not have to use all those words, and you can use others.

3. For each reaction, as described by the equation below, indicate whether it is endothermic or exothermic. Be sure to indicate each reaction with its letter.

a. H2O(l) ----> H2O(s)

b. CO2(s) ----> CO2(g)

c. 2Na(s) + 2H2O(l) ----> 2NaOH(aq) + H2(g)

d. 2H2(g) + O2(g) ----> 2H2O(g)

4. Consider the following two reactions. If we had two containers, one holding methane and oxygen, the other holding carbon dioxide and water, in which container is there a greater likelihood of a reaction? Provide a brief explanation if you can.

CH4(g) + 2O2(g) ----> CO2(g) + 2H2O(l)

CO2(g) + 2H2O(l) ----> CH4(g) + 2O2(g)

5. Using enthalpies of formation, Hof, calculate Horxn for the following reaction (note you will need a table of standard enthalpies of formation.)

a) 3NO2(g) + H2O(l) ----> 2HNO3(aq) + NO(g) kJ mol-1

6. Can you specify the most likely sequence of the four images?

Image A
Image B
Image C
Image D

First Image : Second Image : Third Image : Fourth Image :

7. If I flipped a coin 20 times, what is the most likely number of heads and tails?

8. Given the figure below showing 20 gas particles in constant random motion (the image is static, but use your imagination) at time t = 0. If the small red door is open describe what you believe the container would look like after a reasonable period of time.

9. Is there anything about the questions that you feel you do not understand? List your concerns/questions.

10. If there is one question you would like to have answered in lecture, what would that question be?